Maize root distributions strongly associated with water tables in Iowa, USA
Maize root distributions strongly associated with water tables in Iowa, USA
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DOI:
10.1007/s11104-019-04269-6
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发表时间:
2019-11-01
期刊:
影响因子:
4.9
通讯作者:
Archontoulis, Sotirios, V
中科院分区:
文献类型:
--
作者:
Nichols, Virginia A.;Ordonez, Raziel A.;Archontoulis, Sotirios, V
Aims Root distributions determine crop nutrient access and soil carbon input patterns. To date, root distribution data are rare but needed to improve knowledge and prediction of cropping system sustainability. In this study, we sought to (i) quantify variation in maize (Zea mays) and soybean (Glycine max) roots by depth and environment across Iowa, USA and (ii) identify environmental factors explaining the most variation. Methodology Over three years we collected soil cores from 0 to 210 cm in 16 maize and 12 soybean field experiments at grain filling. Root mass, length, carbon (C) and nitrogen (N) were determined at 30 cm increments, coupled with crop, soil, management, and weather-related measurements. Results Percentage of root mass located in the top 30 cm varied from 52 to 94% in maize and 54-84% in soybean. Variation in maize root distributions was strongly associated with depth to water tables, variation in soybean with soil physical attributes. Root C:N ratios were highly variable with no depth-pattern, averaging 20 and 30 for soybean and maize, respectively. In both crops, specific root lengths increased with depth to 60 cm, and thereafter remained constant. Conclusions Field studies of roots should consider depth to water tables and soil moisture measurements, as they influence vertical root distributions.